RFR: 8288140: Avoid redundant Hashtable.get call in Signal.handle [v2]

[Andrey Turbanov]

> https://github.com/openjdk/jdk/blob/bc28baeba9360991e9b7575e1fbe178d873ccfc1/src/java.base/share/classes/jdk/internal/misc/Signal.java#L177-L178
> 
> Instead of separate Hashtable.get/remove calls we can just use value returned by `remove`,
> It results in cleaner and a bit faster code.

Andrey Turbanov has updated the pull request incrementally with one additional commit since the last revision:

  8288140: Avoid redundant Hashtable.get call in Signal.handle
  apply dmlloyd's suggestion

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Changes:
  - all: https://git.openjdk.org/jdk/pull/9100/files
  - new: https://git.openjdk.org/jdk/pull/9100/files/220d3b61..829f9e23

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=jdk&pr=9100&range=01
 - incr: https://webrevs.openjdk.java.net/?repo=jdk&pr=9100&range=00-01

  Stats: 17 lines in 1 file changed: 0 ins; 0 del; 17 mod
  Patch: https://git.openjdk.org/jdk/pull/9100.diff
  Fetch: git fetch https://git.openjdk.org/jdk pull/9100/head:pull/9100

PR: https://git.openjdk.org/jdk/pull/9100